“It’s a chemical cocktail made up of lots of toxins,” said Jeff Gearhart, Research Director of the Ecology Center in the US state of Michigan. The Ecology Center has been monitoring and testing chemical levels in car interiors for years, and has noted some improvement. But Gearhart says there is still work to be done.“There are over 200 chemical compounds found in vehicles,” he said. “Since these chemicals are not regulated, consumers have no way of knowing the dangers they face.”

Just reading a list of the substances is scary enough, and makes your car’s interior sound like a hazmat hall of fame. Benzene, toluene, formaldehyde, and heavy metals are all part of the mix. And the danger of exposure is scarier still. Immediate symptoms can range from a sore throat to headaches, dizziness, allergic reactions and nausea, depending on the sensitivity of an individual.According to the US Environmental Protection Agency, continued exposure to some of these can lead to hormonal disruption, reproductive impacts and damage to the liver, kidneys and central nervous system — or even cancer. It’s that long-term exposure that experts find most worrisome.“People spend over an hour a day in their vehicles on average,” said Gearhart. “Whether it’s adults, children, or pets, we’re concerned about prolonged exposure to toxic chemicals inside the vehicle.”The danger is greatest when the car is new, and that new car smell is most noticeable. This is when components are still unstable and prone to what is called off-gassing — the release of chemical vapours, which leads to the odour. Heat from a vehicle left in the sun can make matters worse, and speed up the chemical reaction. The danger is reduced over time, and experts say the worst is usually over within about six months.The good news? Automakers we spoke with, including Fiat/Chrysler, Ford, General Motors and Honda all say they’ve taken steps to reduce VOC levels in their vehicles, along with other substances of concern (SOCs). They say they’ve accomplished this primarily by using different materials, coatings and adhesives in manufacturing, and all say they are continuing to look for ways to reduce the use of potentially harmful substances in their cars.One known carcinogen that seems to be on the way out is polyvinyl chloride (PVC), which the Ecology Center found was used in virtually all new car interiors in 2006. By 2012, that number was down to 73%. Manufacturers say PVC use continues to decline, and Honda, for one, claims to have eliminated it entirely from interiors of most models.Carmakers say they have also improved cabin air ventilation and filtration systems. Some, such as Ford, say they have switched to the use of more natural fibers and soy-based foam in seat cushions, which does double duty: reducing chemicals while increasing the use of renewable resources. Of course, the jury is still out on the effects of some of these alternate materials in the long term.Many of these changes have come about in response to regulations in Europe, where greater restrictions on the use of chemicals are already in place. The European Union’s REACH program (Registration, Evaluation, Authorization, and restriction of CHemical substances) was implemented to protect people and the environment from hazardous chemicals, and to find less toxic substitutes for use in vehicles and other manufactured and consumer goods. China is said to be developing its own regulations, and the US state of California has passed legislation aimed at doing the same. The US, however, has lagged behind at the federal level, where legislation has been introduced but so far failed to gain traction.In the meantime, experts advise the best thing that buyers can do to limit exposure is to keep car interiors well ventilated, especially during the first six months of ownership. Park in the shade with the windows open when it’s safe to do so, or at least try to air it out before getting inside — especially on hot days.Avoid sitting in the car while it is parked, and use a windshield solar shade to minimize heat buildup. The Ecology Center also advises frequent passes with a microfiber towel and a non-toxic cleaner, especially when a vehicle is new. “Chemicals like to hang out in the dust,” said Gearhart.

And for those who are especially sensitive to chemicals, he suggests making an extended sit behind the wheel part of the test drive, to see if symptoms or irritation start to develop.“Spend time in the vehicle before purchasing it,” said Gearhart. “Or even consider buying a used car.”There are other ways to get that new-car smell, after all.